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Biomedical subjects

T Litovitz

Publications and source records attributed to T Litovitz.

At least 19 recordsLinked to original sources

ELF in vitro exposure systems for inducing uniform electric and magnetic fields in cell culture media.

Many in vitro experiments on the biological effects of extremely low frequency (ELF) electromagnetic fields utilize a uniform external magnetic flux density (B) to expose biological materials. A significant number of researchers do not measure or estimate the resulting electric field strength (E) or current density (J) in the sample medium. The magnitude and spatial distribution of the induced E field are highly dependent on the sample geometry and its relative orientation with respect to the magnetic field. We have studied the E fields induced in several of the most frequently used laboratory culture dishes and flasks under various exposure conditions. Measurements and calculations of the E field distributions in the aqueous sample volume in the containers were performed, and a set of simple, quantitative tables was developed. These tables allow a biological researcher to determine, in a straightforward fashion, the magnitudes and distributions of the electric fields that are induced in the aqueous sample when it is subjected to a uniform, sinusoidal magnetic field of known strength and frequency. In addition, we present a novel exposure technique based on a standard organ culture dish containing two circular, concentric annular rings. Exposure of the organ culture dish to a uniform magnetic field induces different average electric fields in the liquid medium in the inner and outer rings. Results of experiments with this system, which were reported in a separate paper, have shown the dominant role of the magnetically induced E field in producing specific biological effects on cells, in vitro. These results emphasize the need to report data about the induced E field in ELF in-vitro studies, involving magnetic field exposures. Our data tables on E and J in standard containers provide simple means to enable determination of these parameters.

Culture Media

Initial symptoms as predictors of esophageal injury in alkaline corrosive ingestions.

The predictive value of initial clinical evaluation in the management of alkaline corrosive ingestion remains unclear. This multicenter study was designed to determine if specific clinical signs and symptoms following ingestion of alkaline corrosives could predict significant esophageal injury. Alkaline corrosives were defined by a pH greater than or equal to 12. Signs and symptoms previously suggested as predictive of significant esophageal injury were documented on a standardized data form. Esophagoscopy reports were reviewed blinded to initial symptoms. Three hundred thirty-six alkaline-corrosive ingestions were analyzed. The mean number of symptoms reported in patients who did not have esophagoscopy was 1.2, in patients who had esophagoscopy was 3.0, and in patients that had visualized second or third degree esophageal burns was 4.8. Of 88 patients who had esophagoscopy, 63 (72%) had both the esophagoscopy report and initial symptom assessment available. Esophagoscopy was positive, defined as second or third degree esophageal burns, in 18 of 63 cases (29%). All patients with significant burns were symptomatic. No single or group of initially reported signs and symptoms could identify all patients with potentially serious esophageal burns.

Abdominal Pain

Ingestion of cylindrical and button batteries: an analysis of 2382 cases.

During a 7-year period, 2382 cases of battery ingestion were reported to a national registry. Button cells were ingested by 2320 of these patients; 62 patients ingested cylindrical cells. These cases are analyzed to reassess current therapeutic recommendations, hypotheses about battery-induced injury, and strategies for prevention and intervention. Hearing aids were the most common intended use of ingested cells (952 cases, 44.6%); and in 312 (32.8%) of these cases, the battery actually was removed by a child from the child's own aid. Overall, 9.9% of patients were symptomatic. Two children experienced severe esophageal injury following the ingestion of large diameter cells and required repeated dilatation. In this series and in prior reports, most batteries which lodged in the esophagus and caused esophageal injury were large diameter (20 to 23 mm). However, neither battery diameter nor symptom occurrence could be used to detect all patients with esophageal battery position. Outcome was not affected by battery discharge state, but was influenced by chemical system. Lithium cells, with their larger diameters and greater voltage, were associated disproportionately with adverse effects. Mercuric oxide cells were substantially more likely to fragment, compared with other chemical systems. No clinical evidence of mercury toxicity occurred in this series, although one patient demonstrated minimal elevation of blood mercury levels. In this series and 10 prior reports, all patients with elevated blood mercury levels had ingested batteries which fragmented and showed evidence of radio-opaque droplets in the gut. Special monitoring may be advisable for individuals who have ingested 15.6-mm-diameter mercuric oxide cells. Ipecac was administered in 37 cases of button cell ingestion, causing battery expulsion in only one patient. Retrograde battery movement from the stomach to the esophagus necessitating emergent endoscopic retrieval occurred as a complication of ipecac administration in another patient. The use of endoscopic and surgical intervention declined more than fivefold during the study period. Endoscopic retrieval success was a function of battery location, with batteries in the esophagus more readily retrieved than those in more distal gastrointestinal locations (90.0% vs 46.7%, respectively). A current management protocol is presented advocating a noninvasive approach for most cases of button cell ingestion where an esophageal position is excluded. Manufacturers are urged to provide more securely fastened, child-resistant battery compartments on hearing aids as well as other battery-powered products in household use.

Age Factors

Comparison of pediatric poisoning hazards: an analysis of 3.8 million exposure incidents. A report from the American Association of Poison Control Centers.

This analysis of life-threatening and fatal pediatric poisonings was conducted to aid poison prevention educational efforts, guide product reformulations and aversive agent use, reassess over-the-counter status for selected pharmaceuticals, and identify research areas for clinical advances in the treatment of pediatric poisonings. A hazard factor was devised to assess more objectively the pediatric poisoning hazard posed by pharmaceutical and nonpharmaceutical products. By considering the frequency and extent of injury following actual exposures, the hazard factor reflects more than the acute toxicity of individual ingredients and is also influenced by such variables as packaging, accessibility, availability (as a reflection of marketing), formulations, and closure types. Of the 3,810,405 exposures involving children younger than 6 years of age reported to poison centers in 1985 through 1989, 2117 patients experienced a major outcome (life-threatening effect or residual disability) and an additional 111 fatalities occurred. The three most commonly implicated substance categories, accounting for 30.4% of reported exposures, include cosmetics and personal care products, cleaning substances, and plants. All had low hazard factors, with significant hazards being limited to a small number of products identified herein. Thus this analysis of hazard factors demonstrates that frequent exposure does not imply toxicity. Iron supplements were the single most frequent cause of pediatric unintentional ingestion fatalities, accounting for 30.2% of reported pediatric pharmaceutical unintentional ingestion fatalities reported over an 8-year period. Antidepressants, cardiovascular medications, and methyl salicylate follow in frequency of pediatric pharmaceutical deaths. Hydrocarbons (including five lamp oil deaths) and pesticides were each implicated in 12 pediatric ingestion fatalities during the 8-year period.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool

The effect of milk on ipecac-induced emesis.

A prospective study at two regional poison centers was undertaken in 500 children under six years of age (mean age 2.3 y) to resolve the question of whether milk has an effect on ipecac-induced emesis. When home administration of ipecac was recommended, parents were asked to select either milk or clear fluids. The mean volume of fluid +/- standard deviation administered was 159 +/- 72 mL in the milk group and 161 +/- 77 mL in the clear fluid group (p = 0.79). There was no difference in the onset of vomiting (23.4 +/- 18.5 vs. 23.3 +/- 12.9 min, p = 0.92), number of vomiting episodes (3.5 +/- 1.9 vs. 3.4 +/- 1.8, p = 0.65), or duration of vomiting (45 +/- 73 vs. 39 +/- 54 min, p = 0.31) for the milk group compared with the clear fluid group. Side effects including lethargy and diarrhea occurred with similar frequency in both groups. The substance ingested had no effect on onset of vomiting, vomiting duration or number of vomiting episodes. These findings again demonstrate that milk does not interfere with ipecac-induced emesis.

Animals

Accidental ingestions of oral prescription drugs: a multicenter survey.

Accidental ingestion of oral prescription drugs by children under age five continues to be a public health problem. A telephone survey of 1,866 ingestion incidents reported to nine poison control centers was conducted in the spring of 1986. Accidental ingestion occurred most often with a two-year-old child (42 per cent) in their own home (82 per cent). Thirty-five per cent of the toxic drugs ingested at home belonged to someone other than the immediate family, most often a grandparent. Toxic drugs were more often out of their usual storage location and in non-child-resistant prescription packaging, a nonprescription container, or in no container. Twenty-two per cent of all child-resistant packages were non-functional. Overall, at least 61 per cent of all medications had no child-resistant barrier at the time of ingestion. Accessible storage locations such as the kitchen counter, table top, or top of a dresser or bedside table greatly increased the risk of accidental ingestion. These results suggest the need for effective child-resistant packaging that is easier for all adults to use.

Administration, Oral

Cimetidine toxicity: an assessment of 881 cases.

We reviewed 881 documented cimetidine overdoses. The data were compiled and analyzed retrospectively from 2,612,236 poisoning cases reported to two nationwide poison surveillance systems from 1978 through 1985. Only cases of cimetidine exposures without coingestants were included. Age, sex, symptom occurrence, treatment site, reason and route of exposure, and medical outcome data were evaluated. Eight hundred eighty-one cases met the criteria and were analyzed. Children between 12 and 35 months of age accounted for 43% of the cases and 97% of all exposures were acute. Intentional overdosage accounted for 21%; 76% were accidental in nature. Gastric emptying was performed in 34%. No symptoms were observed in 79% of the cases, which included ingestions of up to 15 g of cimetidine. Only three patients had moderate clinical manifestations. No patients had major medical complications and there were no fatalities. Even patients in the moderate category experienced no life-threatening toxic manifestations. Cimetidine appears to have an extremely high therapeutic index in both children and adults and demonstrates a remarkable safety profile following acute overdose.

Accidents, Home

Miniature battery foreign bodies in auditory and nasal cavities.

A series of cases involving button batteries lodged in the ear or nasal cavity is presented. All produced tissue destruction. Injuries were generally severe, and included tympanic membrane perforation (three patients) or total destruction (three), marked necrosis of dermis of the external ear canal with exposed bone (seven), documented further impairment of hearing (three), destruction of ossicles (two), facial nerve paralysis and chondritis (one), nasal septal perforation (one), and superficial burns of nasal mucosa (one). Otic and nasal drops must be withheld as they provide an external electrolyte bath for the battery, enhancing leakage and generation of an external current, with subsequent tissue electrolysis and hydroxide formation. Instead, batteries lodged in the ear or nose must be removed promptly.

Aged

The alcohols: ethanol, methanol, isopropanol, ethylene glycol.

More than 6 per cent of poisonings involve alcohols and glycols, reflecting their availability in a wide range of household products, including aftershave, brake fluid, gas line antifreeze, model airplane fuel, mouthwash, rubbing alcohol, and windshield washing solution. Diagnosis involves recognition of an osmolal gap and variable degrees and delays in development of an anion gap metabolic acidosis. Therapeutic modalities are similar for methanol and ethylene glycol, both cases requiring ethanol-blocking of alcohol dehydrogenase and hemodialysis. More often, treatment of ethanol and isopropanol poisoning is limited to supportive care.

1-Propanol

Azalea toxicity: an overrated problem?

One-hundred-and-fifty-two azalea ingestions reported to two regional poison centers over a three year period are reviewed. Twenty-eight exposures were the result of sucking nectar from the flower; the remainder involved ingestion of leaves or flowers. Nine patients developed symptoms, but these were minor or probably unrelated in eight. A single patient was significantly symptomatic, experiencing repeated vomiting and transient hypertension. Emergency department treatment was rendered in 9.2% of patients, and hospital admission for less than 24 hours was required in only one case. Ingestion of moderate amounts of azalea pose little toxic hazard.

Adolescent

Button battery ingestion: assessment of therapeutic modalities and battery discharge state.

Button batteries immersed in a simulated gastric environment (0.1N hydrochloric acid) demonstrated less crimp dissolution (corrosion of the metal can) after the addition of neutralizing doses of eight of nine antacids tested. Of 64 ingestion episodes in dogs, clinical manifestations of button battery-induced injury were limited to a single animal developing guaiac-positive stools. Endoscopic lesions included only mild gastritis, occurring with a frequency comparable to that observed in dogs prior to battery ingestion. After ingestion blood mercury levels were not significantly elevated. Crimp dissolution was absent in discharged cells, implying a decreased risk of electrolyte leakage or subsequent tissue injury in patients who ingest spent cells. No protective effect of metoclopramide, cimetidine, or magnesium citrate could be demonstrated in the canine model.

Animals